It is proposed in continuation of Part A of this project to identify the sites at which subunits of glyceraldehyde-3 phosphate dehydrogenase are altered and to evaluate their contributions to the atypical ligand binding properties of the protein and their role, if any, in the pathway of protein degradation. Part B of this project will be devoted to the physical properties of glycogen phosphorylase of liver and the complex of liver glycogen with glycogen-metabolizing enzymes.